ABSTRACT A shortage of primary care physicians makes it difficult to deliver quality diabetes care to America?s aging population. A frequently recommended approach to compensate for escalating primary care physician shortages, while still meeting the chronic illness care needs of an aging population, is to incorporate physician assistants (PAs) and nurse practitioners (NPs) into primary care teams. While a number of team models incorporating PA&NPs have delivered quality care to patients with chronic illnesses such as diabetes, data is limited regarding which clinician team approaches are most effective. Identifying effective approaches to incorporating PA&NPs into primary care teams that care for older patients will require identification of effective PA&NP roles, as well as features of PA&NP and physician interaction (interdependence and coordination) that can improve patient outcomes. Interdependence between primary care PA&NPs and physicians occurs when they provide care to, or ?share? common patients. Managing shared patients between clinicians requires coordination. Coordination can be accomplished through multiple methods including routines (ex: clinical pathways), boundary spanners (ex: case managers), team meetings (ex: huddles), and relational coordination (i.e., communication and relationships) and is believed to be a key mechanism by which clinician teams will improve patient outcomes, particularly for older, complex patients with multiple chronic conditions. Focus has been placed on improving patient outcomes by coordinating care between settings, such as between specialists and primary care. To our knowledge, however, no studies have evaluated the impact of interdependence and/or coordination within primary care on patient diabetes outcomes such as glycemic and lipid control or development of patient treatment goals. My long-term goal is to improve chronic illness care for older complex patients through identification and implementation of effective primary care teams. In order to develop and evaluate team interventions, it is critical to address the medical and social aspects of team-based care delivery. Designing and evaluating interventions that address both aspects of team care require a range of knowledge and skills, including expertise in mixed methods research approaches, organizational theory, and implementation science. The objective of this application is to determine if PA&NP and physician interaction (interdependence and coordination) on teams impacts outcomes for older patients with diabetes. My health policy background, clinical experience as a PA, and formal quantitative research training will provide the foundation for the proposed project. I will pursue career development in mixed methods, and implementation science and organizational theory at both Duke University and the University of North Carolina Chapel Hill (UNC). The specific aims of the proposed project are to describe the methods of coordination utilized between PA&NPs and physicians on primary care teams (Aim 1), to evaluate the relationship between the interdependence of PA&NPs and physicians on primary care teams and outcomes (glycemic and lipid control as well as patient treatment goals) for older patients with diabetes (Aim 2), and to determine if methods of coordination mediate the relationship between PA&NP role, interdependence and outcomes for older patients with diabetes (Aim 3). To achieve these aims, I propose a mixed methods approach. I will collaborate with Duke Primary Care to conduct interviews and surveys with health care professionals from Duke?s clinics regarding the full range of coordination mechanisms used within their teams and practices (Aim 1). This information will be combined with data derived from electronic health records for medically complex patients over the age of 65 with diabetes in order to match PA&NP and physician interactions (Aim 2) with patient outcomes (Aim 3). Synthesis of Aims 1-3 will inform development of a primary care team-based intervention involving clinician interdependence and coordination for an R01 proposal aimed at improving chronic disease management in complex older patients with diabetes. This proposal sets forth essential development steps that are analogous to preclinical/phase 1 studies that are pivotal to guide later successful intervention trials. Skills gained in organizational psychology, mixed methods and implementation science will complement my prior clinical and research training to position me for success as an independent health services researcher with the skills to design and implement health care teams that improve chronic disease management for complex older patients.